1. Field of the Invention
The present invention relates to a vehicle recognition support system to be used by vehicles for recognizing the position of the other vehicle by wireless communication, and informing the driver. More specifically, the invention relates to a vehicle recognition support system in which a vehicle that is not provided with a navigation function establishes a communication link with a neighboring vehicle provided with a navigation function to obtain navigation information, so that each vehicle can recognize its relative position with respect to the other vehicle.
2. Description of Background Art
In order to reduce traffic accident and its damages, improvements have been made to both two- and four-wheeled vehicles. These include improving the eye-catching property of two-wheeled vehicles by illumination of heads light in the daytime, and providing ABS and airbags for four-wheeled vehicles. However, in the case of two-wheeled vehicles, further reduction of accidents through preventive safety measures is important. According to the past accident data, it is said that the main contributing factors to accidents are a wrong determination due to false recognition of the distance from or the speed of the second party (two-wheeled vehicle), not looking ahead carefully, or late recognition by lack of confirmation of safe conditions by drivers of nearby four-wheeled vehicles. “Wrong determination” is generally caused by the fact that the two-wheeled vehicle is apt to be perceived to be at a position farther away from and to be moving slower than it actually is. This is because the front projected area of a two-wheeled vehicle is smaller than that of the four-wheeled vehicle.
One of the contributing factors of “late recognition” is the fact that the two-wheel vehicle tends to be assimilated into the background when a large vehicle such as a track or a bus is traveling behind the two-wheeled vehicle, and that the visual range of the driver on the right turning vehicle is impaired by the on-coming right turning vehicle or other vehicles, which generates a dead angle.
Since the visual perceptive function of human being is such that the wider the width of the vehicle body, the easier recognition of the approaching speed and the relative distance becomes, and since accurately perceiving the speed and distance is easier with familiar objects (four-wheeled vehicles), wrong perception seems to occur more frequently when viewing two-wheeled vehicles. Therefore, for their self-defense, riders of two-wheeled vehicles are required to have positive means for foreseeing and forecasting objects in their surroundings.
In order to address the aforementioned issues, the following alarm system is proposed in JP-A-11-353594.
In this disclosure, when a turning vehicle (four-wheeled vehicle) turning beyond the opposite lane issues a detection signal, and a vehicle in the through traffic lane (two-wheeled vehicle) that is driving straight ahead on the opposite lane returns a reply signal in response to the detection signal, the turning vehicle is able to calculate the relative distance R between itself and the vehicle in the through traffic. When the relative distance R is shorter than the reference distance (Rref), the turning vehicle (four-wheeled vehicle) gives an alarm to the driver of the turning vehicle, and simultaneously, issues a annunciation signal to the vehicle in the opposite through traffic lane. The vehicle in the opposite through traffic lane receives the annunciation signal and gives an alarm to the driver of that vehicle.
In JP-A-11-353592, another alarm system is proposed as follows.
In this case, when the vehicle (four-wheeled vehicle) that is just turning issues a detection signal toward the dead angle of the turning direction, and a replay signal is returned to the detection signal from the other vehicle, the turning vehicle calculates the relative distance R between itself and the other vehicle. When the relative distance R is shorter than the reference distance Rref, the turning vehicle (four-wheeled vehicle) issues an alarm to the driver of the four wheeled-vehicle, and simultaneously, issues an annunciation signal to the aforementioned other vehicle. The other vehicle in the through traffic lane issues an alarm to the driver of that vehicle.
In the related art described above, the two-wheeled vehicles start the “other vehicle recognition process” with reception of detection signal sent from the turning vehicle (four-wheeled vehicle), and thus are unable to detect vehicles other than those that detect them first. When these two-wheeled vehicles turn as well, they have no means to let other vehicles recognize their actions.
Such a technical problem can be solved by mounting a position survey system such as GPS and a navigation system on every vehicle so that the vehicles approaching the traffic intersection communicate with respect to each other to recognize the position of the respective vehicles.
However, since two-wheeled vehicles having only a small storage space, the types of vehicle that can accommodate the navigation system are limited to larger and heavier two-wheeled vehicles. In addition, it is difficult to mount a costly navigation system on a less expensive two-wheel vehicle in comparison with the four-wheeled vehicle.
Accordingly, it is an object of the invention to provide a vehicle recognition support system that can solve the problems in the related art, by enabling the two-wheeled vehicle to recognize the position of the traffic intersection and give notice to other vehicles without the need for mounting a navigation system on the two-wheeled vehicle.